feat: add new indicators (Decay, Edecay, MinusDi, MinusDm, PlusDi, PlusDm, Maxindex, Minindex, Sarext) and update pine scripts, core libs, validation tests, and python bindings

lib/statistics/kendall/Kendall.cs

@@ -34,6 +34,7 @@ public sealed class Kendall : AbstractBase
 
     private const double Epsilon = 1e-10;
 
+    /// <inheritdoc />
     public override bool IsHot => _bufferX.Count >= 2;
 
     /// <summary>
@@ -88,16 +89,23 @@ public sealed class Kendall : AbstractBase
     /// <summary>
     /// Updates with raw double values.
     /// </summary>
+    /// <remarks>
+    /// Stamps both inputs with <c>DateTime.UtcNow</c> as their timestamp. For
+    /// deterministic or replay-safe sequences use
+    /// <see cref="Update(TValue, TValue, bool)"/> with explicit timestamps instead.
+    /// </remarks>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public TValue Update(double seriesX, double seriesY, bool isNew = true)
     {
         return Update(new TValue(DateTime.UtcNow, seriesX), new TValue(DateTime.UtcNow, seriesY), isNew);
     }
+    /// <summary>Not supported. This indicator requires two inputs; use <see cref="Update(TValue, TValue, bool)"/> instead.</summary>
     /// <remarks>Not supported for dual-input indicator. Use Update(seriesX, seriesY) instead.</remarks>
     public override TValue Update(TValue input, bool isNew = true)
     {
         throw new NotSupportedException("Kendall requires two inputs (seriesX and seriesY). Use Update(seriesX, seriesY).");
     }
+    /// <summary>Not supported. This indicator requires two inputs; use <see cref="Batch(TSeries, TSeries, int)"/> instead.</summary>
     /// <remarks>Not supported for dual-input indicator. Use Batch(seriesX, seriesY, period) instead.</remarks>
     public override TSeries Update(TSeries source)
     {
@@ -169,11 +177,13 @@ public sealed class Kendall : AbstractBase
 
         return (concordant - discordant) / denominator;
     }
+    /// <summary>Not supported. This indicator requires two input spans.</summary>
     public override void Prime(ReadOnlySpan<double> source, TimeSpan? step = null)
     {
         throw new NotSupportedException("Kendall requires two inputs.");
     }
 
+    /// <inheritdoc />
     public override void Reset()
     {
         _bufferX.Clear();
@@ -268,6 +278,9 @@ public sealed class Kendall : AbstractBase
         }
     }
 
+    /// <summary>
+    /// Calculates Kendall Tau-a for two time series and returns both the result series and the live indicator instance.
+    /// </summary>
     public static (TSeries Results, Kendall Indicator) Calculate(TSeries seriesX, TSeries seriesY, int period = 20)
     {
         var indicator = new Kendall(period);

lib/statistics/kendall/kendall.pine

@@ -1,4 +1,4 @@
-// The MIT License (MIT)
+// Licensed under the Apache License, Version 2.0
 // © mihakralj
 //@version=6
 indicator("Kendall Rank Correlation (KENDALL)", "KENDALL", overlay=false, precision=4)